The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1887-03-20
BRIDGE CONSTRUCTION.
New Ideas Brought Forth by the Recent
Disaster at Forest Hills.

New Ideas Brought Forth by the Recent
Disaster at Forest Hills.
Special to the Indianapolis journal:
NEW YORK, March 19-The following expert
opinions regarding bridge construction sug-
gested by recent railroad disasters contain much
that is new:
Capt Samuel Probasco assistant engineer of
the Brooklyn bridge. said: 81 have read all the
accounts of the Forest Hills accident, but the
facts given are so meagre and contradictory that
l have not been able to come to any definite
clusion. An iron bridge ought to be the best
bridge in the world, and always is when good
metal, good workmanship and good construction
united. What accidents l remember, in
voiving iron bridges, arose sometimes. but
rarely, from poor metal, more frequently from
inferior rolling poor welding. and most of all
from the train itself. In one case on the Read
ing railroad. car-axle of a moving car broke,
the truck was thrown down, and moved by the
force of the train fractured a truss beam and so
wrecked the train. 1t is said that long Earring
will make iron as brittle as glass. While
this seems true theoretically In certain cases.
it is not borne out by the facts. There ara
iron bridges over fifty years old that have
examined that, SO far as any one can see, are
as good and strong to-day as when they were
first erected. Iron bridge building has under
gone great change for the better in the past
ten years, the business now being almost monop-
olized BY q few large corporations and the quail
ity Of the metal workmanship and construction
being brought to high state of perfection. [
do not understand exactly what they mean by
the Forest Hills bridge not being anchored. II
they mean securely fastened to the abutments
so that it could not move, they are talking non
sense. Any iron bridge must be allowed free
room for the contraction and expansion caused
by the changes in temperature. Otherwise the
bridge would tear something loose somewhere.
On the Brooklyn bridge we have three breaks in
the metal work to allow for this motion"
Col. F. K. Hahn, superintendent of the New
York Elevated railroad, said: II have formed no
opinion in regard to the disaster, as am in pos
session of no facts l believe it advisable to an
Choir, or rather fasten. iron bridges, and do not
believe that iron beams weaken with use from
vibration. AS respects the cause, can only say
that it would not be III my place to comment
upon it, except to remark that the Boston e
Providence is one OF the best-managed roads in
this country"
J. r. Smith, prominent engineer and rail-
road builder, said: Il am unable to determine
whether the railroad accident at Forest Hills re-
suited from any imperfection in the bridge or
from something that occurred TO the train. In
very many such cases the latter rather than the
| former is the real cause of the trouble. An axle
| may break. truck may get out of order con-
| Meeting rod may be fractured or a fat wheel
| may slip, and any one Of these may derail q
! train and so crash through bridge. It looks,
however, as If there had been some careless con-
struction Of the Forest Hills viaducts in regard
to the extremities of the iron beams. These to-
|
provement in New York CITY, are so arranged
| as to provide for the expansion caused by hot
| weather. and at the same time fastened securely
| SO as to prevent lateral motion, or spreading,
and axial motion beyond the requisite expan-
| sion. This latter is what the newspaper reports
mean suppose, by anchoring. As to weaken
ing by long vibration, do not believe it amounts
| to anything"
Edward Wyman, G. E., said: Judging from
the later reports have read of the Forest Hills
| accident, think it arose from hangers made OF
4 inferior iron Or STEEL or else Of good metal con
tanning large flaw or improperly welded. Gen
orally it is difficult to provide absolutely against
| this contingency. Despite every care, one bad
hanger may slip in among lot, and if it occu
pies responsible position, an accident may oc
cur. Iron wears, might say, forever. Columns
on the old Gilbert elevated that were taken ou
after years of use, for fear that they might b.
/ weakened, proved upon experiment to be as
strong as on the day they were put up. In fact
| the success of the New York elevated roads. a.
well az Of the great iron bridges of the Ole